KAPOSIS SARCOMA - HISTOCHEMICAL AND ELECTRON MICROSCOPIC STUDIES

[摘要] Histochemical and electron microscopic studies of 4 cases of Kaposi''s sarcoma revealed that the tumor was composed mainly of 2 types of cells, that is, proliferating endothelial cells and proliferating perithelial cells. The latter develope into phagocytic fib-roblasts. The proliferating endothelial cells showed a weak reaction for non-specific alkaline phosphatase, whereas the mature vessels present in the tumor showed a strong enzymatic reaction. In electron microscopic studies the endothelial cells showed only a small number of lyso-somes which contained sparsely distributed ferritin particles. The phagocytic fibroblasts appeared to originate from the perithelial cells of proliferating vessels. The phagocytic fibroblasts were seen to produce immature collagenous fibrils. The ferritin containing organelles seen in the cytoplasm of phagocytic fibroblasts were identified as lysosomes on the basis that they showed by electron microscopy non-specific acid phosphatase activity and structural characteristics compatible with lysosomes and by histochemistry positive reactions for non-specific acid phosphatase, [beta] -glucuronidase, PAS (periodic acid Schiff) and Sudan Black B stains. The multi-laminated bodies often found in the phagocytic fibroblast were identified as the residual bodies of lysosomes and not as nyelin sheath of schwannian cells.